Treating articles with volatile solvents



I April 28, 1942. e. EDHOFER EI'AL 2,230,811 'fREATING ARTICLES WITHVOLATILE SOLVENTS Filed Oct. 6, 1959 Z SheetS-Sheet 1 I N -1NVENTOR5GEORG' EaHor-E'R, By GEORG" OLFf-T ATTC) EYS 2 S heets-Sheet 2 o o o 0l0 0 0 0 0 0 G. EDHOFER EIAL TREATING ARTICLES WITH VOLATIL E SOLVENTSFiled Oct. 6, 1939 April 2 1942.

G'soecfo oizl BY GEOEG'PVOLFE W 4- ATTO Y.

Patented Apr. 28, 1942' TREATING ARTICLES WITH VOLATILE SOLVENTS GeorgEdhofer and Georg Wolff, Munich, Germany, assignors to Dr. AlexanderWaclrer Ges. fiir elektrochemische Industrie m. b. 11., Munich, Germany,a corporation ApplicationOctober 6, 1939, Serial No. 298,184

' In Germany January 16, 1939 7 Claims.

The present invention relates to an apparatus for treating articles withvolatile solvents, particularly to the provision of a loading chamberand loading door in apparatus of the type set forth and of suction meanswhich operate in dependence on the position of said door.

It is known to treat articles in order to remove grease therefrom withvolatile organic solvents such as: trichlorethylene, perchloroethylene,carbon tetrachloride, benzine, benzol and the like and to useffor suchtreatment a vessel in which the articles are moved through the solventby means of mechanical conveyors. Because of the volatility of thesolvents it is unavoidable that solvent vapor is developed particularlyif the solvents are used at boiling temperature. It is also well knownto condense the vapor in the treating chamber by suitable cooling meanswhereby the treated articles particularly when they are made of metalare dried as soon as they are moved from the hot solvent into thecooling zone above the solvent; in spite of such condensing means acertain amount of vapor is present in the cooling zone due to diffusionand it is necessary to prevent the escape of the air containing suchvapor from leaving the treating chamber in order to avoid annoyance. Acomplete air-tight construction of the treating chamber is notsufllcient to accomplish this because they must be periodically a dooropened for exchanging the articles to be treated. The escape of the aircontaining undesirable vapor can be prevented to a certain extent byremoving the air containing the vapor by means of suction; this method,however, causes a great loss of solvent and does not completely preventcarrying of the vapor and the solvent to the outside which adheres tothe articles to be treated particularly not when such articles havecavities which may contain solvent even in liquid state.

It is an object of the present invention to correct the above mentionedshortcomings by the provision of a special loading chamber, the interiorof which is subjected to suction and which is provided with a loadingopening and an upper opening which communicates with the interior of thetreating chamber and which is otherwise completely closed on the sidesand on the bottom. The articles to be treated are put on the conveyor insaid loadingchamber and the conveyor carries the articles through thetop opening of the loading chamber into the treating chamber and thenagain through said top opening back into the loading chamber. Suctionmeans are provided only in saidloading chamber which i absolutelyimpossible,

Further and other objects and advantages of the present invention willbe apparent from the accompanying specification and claims and shown inthe drawings which, by way of illustration, show what we now consider tobe a preferred embodiment of our invention.

In the drawings:

Figure 1 is a diagrammatic cross sectional view of the apparatusaccording to the present invention.

Figure 2 is a sectional view of the apparatus I according to the presentinvention taken along line 2-2 of Figure 1.

Figure 3 is a diagrammatic cross sectional view of a modified apparatusaccording to the present invention.

Figure 4 is a sectional view taken along line 4-4 of Figure 3.

Like parts are designated by like numerals in all figures oi thedrawings.

The treating chamber i is completely closed but for the loading opening8. A conveyor having'two chains 2 which are conducted and held inposition by means of guide rollers and to which at equal distancescarriers 3 are connected which carry the articles to be treatedinbaskets 4 is provided within the treating chamber and transports thearticles to be treated consecutively through a plurality of individualchamhers 5 which are provided in the lower part of the treating chamberand which are filled with solvent. The carriers 3 are so distributed onthe endless chains 2 that there is always a plurality of baskets 4immersed in the solvent and one of the other baskets disposed in theloading chamber fi'ythe' latter is positioned in the upper part of thetreating chamber l and extends from one sidewall of said chamber to theother side wall. The'loading chamber 6 is open on top in order toprovide for the free entrance and exit of the baskets and is completelyseparated from connected with the loading chamber. A suction pump I3 isconnected with the suction conduit 9 and the pump I3 is connected anddriven by electrical motor it. Instead of providing the motor pump unitl3, l4 conduit 9 may be connected to another source of suction. Freshair enters through the loading opening 8 into the loading chamber 6 tothe same extent as air containing solvent vapor is removed throughsuction conduit 9 from the loading chamber so that no solvent vapor canaccumulate in the loading chamber and the treated articles are quicklyand completely freed from solvent which may adhere v to said articles. vI

Whenever a loaded basket is brought into the loading chamber 6 by meansof the conveyor the conveyor is stopped in order to provide time for acomplete removal of the air which may be loaded with vapor from thearticles, and exchange of the treated articles for new untreatedarticles; after the exchange is carried out through the loading opening8, -the conveyor is again 'started and the newly inserted basket startsits passage through the treating chamber and makes room for the nextbasket entering the treating chamber. If the operation is to bediscontinued for a longer period of time, the loading opening 8 isclosed by means of the door I and suction is discontinued; the latter ispreferably accomplished by providing an electric switch i 0 theoperation of which is dependent on the position of the door I. Theswitch I0 interrupts the flow of electric current to motor ll wheneverthe door I is closed. n

For operating with heated solvent a gas heater ll may be provided at thebottom of the'treating chamber and a cooling system I! may be providedin the vapor space of the treating chamber; when operation of theapparatus is discontinued for a long period of time, of course, thefuel'supply to the heater H and the cooling agent supply to the'systemI! must be interrupted.

Without departing from the scope of the present invention, the apparatusillustrated in the drawings can be changed. For example, the loadingchamber may be located, instead 01' substantially in the center of thetreating chamber, at some other place in the interior of said chamber orit may be attached to the outside of the treating chamber. The conveyormay be provided with well known means for swinging or for revolving thebaskets; depending on the configuration of the articles to be treated,the baskets may be omitted and the articles connected directly or bymeans of suitable frames with the conveyor.

Figures 3 and 4 show an embodiment of the present inventionin which theloading chamber 6' is not directly within the main treating cham- -ber Ibut adjacent thereto. The open top of the loading chamber communicateswith the interior ofthe treating chamber. The loading chamber 6' isflanged to the side of the treating chamber I and is provided with anoutlet 9 through which air and vapor is permanently withdrawn from theloading chamber.

In the embodiment of the invention shown in Figures 3 and 4 drums 4' areused instead of the baskets 4 shown in Figuresl and 2. The drums l aresupported in the center by means of the brackets 3' and may rotate whilethey travel through the treating chamber.

We claim:

1. An apparatus for treating articles with volatile solvents comprisinga treatingchamber, a combined loading and unloading, chamber having anopening in its upper part, said opening communicating. with the interiorof said treating chamber, a conveyor within said treating and loadingchambers'for moving the articles to be treated through said chambersandthrough said opening, a suction conduit connected tothe lower part ofsaid loading and unloading chamber, and a door in one side of andconnecting said loading and unloading chamber with the outside andproviding exit and entry for thearticles to be treated.

2. An apparatus for treating articles with volatile solvents, comprisinga treatingchamber, a loading chamber having an opening in its up erpart, said opening communicating with the interior of said treatingchamber, a conveyor within said treatingand loading chamber and movingthe articles to be treated through said chambers, and a suction conduitconnected to the lower part of saidloading chamber, said loading chamberbeing disposed within said treating chamber and having a door connectingsaid loading chamed to thelower part of said loading chamber, saidtreating chamber and said loading chamber having a wall portion incommon which is substantially parallel to the plane in which saidconveyor -moves, and a loading door in said wall portion.

4. An apparatus for treating articles with volatile solvents comprisinga treating chamber, a loading chamber having an opening in its upperpart which opening communicates with the interior of said treatingchamber, a conveyor within said treating and loading chamber andcarrying the articles to be treated through said chambers and throughsaid opening, a suction conduit connected to the lower part of saidloading chamber, said loading chamber having a door to the outside andbeing disposed opposite'said suction conduit.

5. An apparatus for treating articles with volatile solvents comprisinga treating chamber, a loading chamber having an opening in its upperpart which opening communicates with the interior of said treatingchamber, a conveyor with in said treating and loading chamber andcarrying the articles to be treated through said chambers and throughsaid opening. a suction conduit connected to the lower part of saidloading chamber, suction supply means connected with said conduit, adoor connecting said loading chamber with the outside, suction controlmeans connected with said door 'and with said suction supply means andcontrolling the supply of suction in dependence on the position of saiddoor.

6. An apparatus for treating articles with vola-i tile solventscomprising a treating chamber, a loading chamber having an opening inits upper part which opening communicates with the interior of saidtreating chamber, a conveyor within said treating and loading chamberand carrying the articles to be treated through said chambers andthrough said opening, a suction conduit connected to the lower part ofsaid loading chamber, said treating chamber being completely closed butfor the opening with which it communicates with said loading chamber.

7. An apparatus as claimed in claim 1 which said loading and unloadingchamber is disposed at the side of said treating chamber and saidsuction conduit is connected to a side of said loading and unloadingchamber which is opposite the side in which said door is provided.

GEORG EDHOFER. GEORG WOLFF.

